Observing the Heavens Virtually

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Observing the Heavens Virtually

SAN DIEGO – In the near future, anyone with a computer modem and a clever idea may be able to explore the cosmos in a virtual space observatory – online.

The idea of a national virtual observatory, offered as part of the U.S. space community's plan for the next decade, could become reality within five years at an estimated cost of $25 million and a global version could be in place by 2010, according to Stephen Strom, head of planning and development at the National Optical Astronomy Observatory (NOAO).

A lot of astronomical data is already available to the public, through NASA and the space agencies of Europe and Canada. But what scientists envision, in work to be discussed at this week's meeting of the American Astronomical Society in San Diego, is a complete archive of the burgeoning observations from telescopes on the ground and orbiting Earth.

The sheer amount of data can be daunting, because of parallel explosions in the 1990s in the ability of space scientists to collect material and in the capacity of computers to store it, Strom said by telephone from Tucson, Arizona.

"There is a revolution in detective ability; every 18 months, our ability to image the sky doubles," Strom said. Right now, there are many terabytes – trillions of bytes – of astronomical data available for study. By the end of the decade, the amount of data will be many petabytes. Each petabyte is a thousand terabytes.

By contrast, a personal computer these days is considered to have a large memory if its hard drive can hold 20 gigabytes, or 20 billion bytes of information.

If petabytes of space data were available online, Strom said astronomers and others could map so much of the sky that it might be possible to make a digital movie of certain fast-moving features, such as asteroids threatening Earth or comet-like objects orbiting the Sun outside the orbit of the planet Neptune.

George Djorgovski of the California Institute of Technology has been a proponent of the virtual observatory, and was scheduled to offer insights on its creation at the San Diego conference.

Djorgovski has argued that using data from many telescopes – from the orbiting Hubble Space Telescope to the Chandra X-Ray Observatory to Earth-based telescopes – would give unprecedented accuracy in observing celestial phenomena.

Strom and others working on this proposed project recognize that one stumbling block is a cultural one. While the National Aeronautics and Space Administration has long had a principle of sharing data collected on large space missions with the public, the same does not always hold true for scientists working with ground-based observatories.

"The data have been viewed largely ... as the property of the individual investigator,'" Strom said. "We lack the culture of broad public access."

There also needs to be standardization of what would amount to a massive online database of information, aimed at the world's nearly 10,000 astronomical researchers but also available in some form to the public.

"It's not just a repository of information, but tools to deal with it," said David De Young of NOAO, who has also worked on the proposed project.

These tools would help scientists and others recognize patterns in what they were seeing, and would put together impressions of objects using observations from X-ray, gamma ray, radio waves and optical telescopes, giving a more complete picture, De Young said by telephone before his arrival in San Diego.

The virtual observatory would probably mean a change in the perception of the astronomer's job, De Young said.

"There will no longer be the tradition of the lone astronomer in the dark, adjusting the telescope by hand," he said. Instead, many astronomers will just go to their computers and log in.